Bioequivalence and Bioavailability Forum

Hi ElMaestro!

❝ I can understand why regulators prefer to stay with things they know, like Pocock's 0.0294.

Do you think that they know/understand the context of Pocock’s original 0.0294 (superiority testing, parallel groups, fixed total sample size k, normal distribution – Z, known and equal σ², interim look at k/2)?

❝ On one hand we/they/someone need to be very careful when we/they/someone just blindly assume that what works with superiority will also work for equivalence.

Well said.

❝ On the other hand, we should appreciate signals from regulators. They give us something we can base our actual plans on. And besides, I could be completely wrong as I usual am, in practice I think it is just as easy to plan a method B study as a method C study and their sample sizes appear equal also.

Total sample sizes are equal (see Table II), but with very few exceptions Method B more often goes into Stage 2 than Method C. That’s a consequence of B’s penalty in Stage 1.

❝ I am happy with either.

I’m happy with B and very happy with C.

❝ I have a feeling the two-stage approaches are going to become more and more prominent for generic developers so there is certainly a need to have these debates.

Yep. Was the topic in one thirds of the chats I had in the coffee-breaks of this week’s workshop in Budapest.